On Fri, Jul 5, 2024 at 6:56 PM David Hildenbrand <david@xxxxxxxxxx> wrote: > > On 05.07.24 12:48, Lance Yang wrote: > > Hi David and Barry, > > > > Thanks a lot for paying attention! > > > > On Fri, Jul 5, 2024 at 6:14 PM David Hildenbrand <david@xxxxxxxxxx> wrote: > >> > >> On 05.07.24 12:12, Barry Song wrote: > >>> On Fri, Jul 5, 2024 at 9:08 PM David Hildenbrand <david@xxxxxxxxxx> wrote: > >>>> > >>>>> @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, > >>>>> i_mmap_unlock_read(mapping); > >>>>> out: > >>>>> xas_destroy(&xas); > >>>>> - if (is_thp) > >>>>> + if (order >= HPAGE_PMD_ORDER) > >>>> > >>>> We likely should be using "== HPAGE_PMD_ORDER" here, to be safe for the > >>>> future. > >>> > >>> I feel this might need to be separate since all other places are using > >>> folio_test_pmd_mappable() ? > >> > >> Likely, but as you are moving away from this ... this counter here does > >> and will always only care about HPAGE_PMD_ORDER. > > > > I appreciate the different opinions on whether we should use > > ">= HPAGE_PMD_ORDER" or "==" for this check. > > > > In this context, let's leave it as is and stay consistent with > > folio_test_pmd_mappable() by using ">= HPAGE_PMD_ORDER", > > what do you think? > > I don't think it's a good idea to add more wrong code that is even > harder to grep (folio_test_pmd_mappable would give you candidates that > might need attention). But I don't care too much. Maybe someone here can > volunteer to clean up these instances to make sure we check PMD-size and > not PMD-mappable for these counters that are for PMD-sized folios only, > even in the future with larger folios? Thanks for clarifying! Yes, agreed. We should ensure we check PMD-size, not PMD-mappable here, especially as we consider large folios in the future. So, let's use "== HPAGE_PMD_ORDER" here ;) Thanks, Lance > > -- > Cheers, > > David / dhildenb >
